Pentagon

A pentagon is a five-sided polygon. It is a two-dimensional shape with five straight sides and five angles. The sum of the interior angles of a pentagon is always 540 degrees.

There are different types of pentagons, including regular and irregular pentagons. A regular pentagon has all sides and angles equal in measure, while an irregular pentagon has sides and/or angles that are not equal.

The area of a regular pentagon can be calculated using the formula:

A = (5/4) * s * √(5(5+2√5)),

where A is the area and s is the length of one side.

The perimeter of a pentagon can be found by adding the lengths of all its five sides together.

Examples of real-life pentagons include the shape of home plate in baseball, the design of the Pentagon building in Washington, D.C., and the petals of many flowers.

◂Math Worksheets and Study Guides Third Grade. Perimeter

The resources above cover the following skills:

Geometry (NCTM)

Analyze characteristics and properties of two- and three-dimensional geometric shapes and develop mathematical arguments about geometric relationships.

Identify, compare, and analyze attributes of two- and three-dimensional shapes and develop vocabulary to describe the attributes.

Use visualization, spatial reasoning, and geometric modeling to solve problems.

Use geometric models to solve problems in other areas of mathematics, such as number and measurement.

Connections to the Grade 3 Focal Points (NCTM)

Measurement: Students in grade 3 strengthen their understanding of fractions as they confront problems in linear measurement that call for more precision than the whole unit allowed them in their work in grade 2. They develop their facility in measuring with fractional parts of linear units. Students develop measurement concepts and skills through experiences in analyzing attributes and properties of two-dimensional objects. They form an understanding of perimeter as a measurable attribute and select appropriate units, strategies, and tools to solve problems involving perimeter.